Vacuum transfer of high density fluids



Sept. 8, 1959 w. D. VEINOT' EI'AL VACUUM TRANSFER OF HIGH DENSITY FLUIDSFiled April 11 1955 3 Sheets-Sheet 1- INVENTORS (Jillian Vn'no? mrsm-Arron/5y;

Sept. 8, 1959 w. n. 'VEINOT E.TAL- 2,903,010

- VACUUM TRANSFER OF HIGH DENSITY FLUIDS Filed April 11, 1955 v 3Sheets-Sheet 2 IN v/ENTORS PATENT HTTORNE') S Sept. 8, 1959 w. D. VEINOTETAL 2,903,010

VACUUM TRANSFER OF HIGH DENSITY mums Filed April 11, 1955 V 3Sheets-Sheet 3 Will/HM D. Vsmor CYR/L Ros/-50 5/ MM9 fa.

WUn er United States Patent VACUUM TRANSFER OF HIGH DENSITY FLUIDSWilliam D. Veinot, Outremont, Quebec, and Cyril Robinson, Montreal,Quebec, Canada, assignors to McColl- Frontenac Oil Company Limited,Montreal, Quebec, Canada Application April 11, 1955, Serial No. 500,544

6 Claims. (Cl. 137-205) This invention relates to an improved method oftransfer of high density fluids by vacuum flow through a systeminvolving change of levels of flow of the fluid to the extent thatvacuum normally applied to the flow system will not cause the fluid toflow through the change of levels to complete the transfer.

The invention is particularly concerned in the transfer of high densityfluids such as tetra ethyl lead from one tank to another, such as from atank car to a storage tank, where safety regulations either prohibitoverhead transfer or specify a height above ground for the transferpiping which would prohibit the use of a vacuum to lift the fluid to theoverhead height required by such regulations; and to overcome the addedheight and subsequent air pockets which are formed when the transferline is taken underground from one tank to another over the interveningdistance separating one tank from the other. When the high density fluidhas to be transferred from say a tank car, under a roadway orintervening railroad tracks to a weigh tank or storage tank which isnormally located above ground level, the fluid must first be taken upout of the tank through an inverted U then through an underground U thenthrough another inverted U down into the tank. In order to overcome thedifliculties of air trapped in the U bends a balance vacuum line andbarometric leg is installed at the highest point of the U bend at thetank car and is connected to the vacuum pump of the fluid transfersystem.

In order to fully understand the nature of this invention reference ismade to the following detail specification and the drawings in which:

Fig. 1 is a diagrammatic showing of the invention installed between atank car and a weigh tank.

Fig. 2 is a line diagram of a complete installation having the necessarycontrol valves etc. for the satisfactory operation of the invention.

Figure 3 is a line diagram similar to Figure 2 but showing the vacuumbalance leg brought underground.

Referring to the drawings, the line diagram shown in Fig. 1 covers atypical installation only and can be modified considerably to suitspecific installations without departing from the spirit of thisapplication. The tank 1 can be either a weigh tank or a storage tankwhile the tank 2 can be either a fixed tank whose location necessitatesthe installation of the present invention or it may be a vehicle orrailroad tank car which cannot approach close enough to the tank 1 fornormal transfer of fluid from one to the other because of such obstaclessuch as ;rail r oad tracks or roadways.

riprn ial conditions where the tank 2 can be te gloss an; tank 1,unloading of the tank 2 into nk 1 c 'acg'zzomplished by means of adirect conallaftiiinff l lowever, where the tanks 1 iCQ and 2 areseparated as shown in the drawing the connecting pipe 3 has to be ledunderground in the form of a U tube with its connections to the tanks 1and 2 forming inverted Us 4 and 5. It is in the inverted US that airpockets are formed. The pocket of air at 4 constitutes a break in theflow of the fluid thereby preventing a siphon-like flow to the tank l.

The normal vacuum obtained at the eductor 6 does not exceed 15 to 20inches of mercury and due to the high density of the fluid, it isimpossible to lift the fluid to the required height. In an attempt tooperate the system without the balance line and barometric leg of thisapplication, at the start of the operation, the fluid would rise to thetop of the inverted U 4 and spill over, filling the lower part of U pipe3 until the vacuum at point A is reduced by I1 and 11 to such an extentthat it is insuflicient to overcome the lift at 11 The flow in thesystem would then stop.

In order to overcome this difliculty a barometric leg 7 is installed,extending upwards to the desired height from the highest point of theinverted U 4. The pipe leg 7 then drops down at 8 to a suitable heightabove ground level to extend overhead at 9, with a slight downwardslope, to connect up with the eductor 6 and vacuum pump 10.Alternatively, the pipe leg 3 can drop a straight down underground tofollow the fluid line 3 to connect up with the eductor 6 and vacuum pump10, should that be found more convenient. This alternative vacuum line9A is shown in Fig. 3 of the drawings. With the installation of thebarometric leg 7 and balance line 8 and 9, complete evacuation of airfrom the top of the inverted U 4 is effected, permitting the completefilling up of the U pipe 3 with fluid from the tank 2. The lift in thesystem is now 12 and the system will continue to function to transferthe high density fluid as long as the vacuum at the eductor 6 exceedsthe head h plus k One preferred embodiment of a permanent installationconsists of the tank 1 having the inlet stand pipe 20 connected with theinverted U pipe 5 through the valve 21. One leg of the U pipe 5 isconnected with the underground pipe 3 through a pair of valves 22between which an H connection 23 leads to auxiliary storage tanks, notshown, controlled by the valves 24 and 25; the other leg of the U pipe 5leads to the pump 10 through the valves 26 and 26A. Between the valve 26and the pump 10 a T connection 27 has a branch leading to the eductor 6whose through connection leads through the valve 28 to a circulatingtank and then back to pump suction. The vacuum balance leg 3 and 9 (oralternatively 9A as shown in Fig. 3) is connected to the eductor vacuummanifold through valve 45. The branch 29 from the eductor 6 is providedwith a check valve 30 and from there a vacuum line 31 controlled by thevalve 32 leads to the stand pipe 20 at a point above the valve 21.Beyond the connection of the vacuum line 31 with the check valve 30, avalve 33 connects directly with the valves 34 and 35. The valve 34controls the line 36, leading to an auxiliary storage tank, not shown,and through a valve 37, to a vent to the atmosphere. The valve 35controls the vacuum line 38 leading to the top of the tank 1. A valve 39in the line 33 controls a vent to atmosphere from this line.

The inverted U 4- comprises a swivel connection 40 to the vertical legof the U pipe 3 and a swivel connection 41 to the stand pipe 42 of thetank 2 through the valve 43. The tank 2 is provided with the vent 46.Above the swivel connection 40 a valve 44 connects the top of theinverted U 4 with the barometric leg 7 and balance pipe 8 and 9 while avalve 45 is inserted at the opposite end of the line 9 adjacent itsconnection with the eductor 6 and pump 10.

In order to operate the system efliciently the operation of transferringhigh density fluid from tank 2 t tank 1 is carried out in the followingmanner.

After the tank 2 has been run into place it is con- 'nected up to thesystem by means of the stand pipe and swivel connections 40 and 41. Allvalves are closed. Valves 28, 33 and 35 are opened and pump til isstarted up to draw a vacuum on the tank 1. After a maximum vacuum hasbeen obtained at the tank 1, valves 32, 26, 22 and 43 are opened and thesystem is then checked for leaks. if the system is tight, close valves32 and 26 and open the valves 44 and 45 in the barometric leg 7 andbalance line 9.

After vacuum gauges have indicated that a vacuum has been established inthe tank car the vent on the top of the tank 2 is opened. Valves 44 and45 are closed when vacuum gauges have indicated that all air has beenevacuated from the top of the inverted U and valve 21 is then opened.Should the tank 1 be a weigh tank, the associated scale will indicatewhen the flow of fluid has started. If the tank is not a weigh tank thenother gauges will indicate when the flow of fluid has started. The fluidin the tank 2 will continue to be evacuated into the system and to thetank 1 until the fluid drops to the level of the stand pipe 42.

By the use of the above described installation the hazards oftransferring highly inflammable fluids such as tetra ethyl lead and thelike are overcome in such a manner as to meet the requirements ofrestrictive 'egulations. The system disclosed also overcomes thedifficulty of lifting a high density fluid such as tetra ethyl lead byvacuum means to the levels necessary when the system has to be takenunderground in the manner shown.

What we claim is:

1. In a system for transferring heavy density fluid from the top of onetank to the top of a second tank comprising, a pipe extending in aseries of reverse U bends underground below and between said tanks, asource of vacuum, means to connect the source of vacuum to the top ofsaid second tank, the height of the U bends in said pipe being such thatfor a given magnitude of the source of vacuum applied to the said secondtank, the heavy density fluid can be lifted to the height of theinverted U adjacent the first of said tanks and spill over but isinsufficient to effect flow from the first to the second tank, and meansto connect the source of vacuum temporarily to the top of the reverse Ubend pipe adjacent the first of said tan is to evacuate the air from thesaid pipe and effect a continuous flow of fluid from the first to thesecond tank.

2. In a system for transferring heavy density fluid from the top of onetank to the top of a second tank comprising, a pipe extending in aseries of reverse U bends underground below and between said tanks, abarometric leg extending upwards from the top of the reverse U bend insaid pipe adjacent the first of said tanks, a source of vacuum, means toconnect the source of vacuum to the top of said second tank, the heightof the U bends in said pipe being such that for a given magnitude of thesource of vacuum applied to the said second tank, the heavy densityfluid can be lifted to the height of the inverted U adjacent the firstof said tanks and spill over but is insuflicient to effect flow from thefirst to the second tank, and means to connect the source of vacuumtemporarily to said barometric leg to evacuate the air therefrom andfrom pipe adjacent said first mentioned tank and effect a continuousflow of fluid from the first to the second tank.

3. In a system for transferring heavy density fiuid bends undergroundbelow and between said tanks, at barometric leg extending upwards fromthe top of the reverse U bend in said pipe adjacent the first of saidtanks, a source of vacuum, a pipe connection connecting said barometricleg with the source of vacuum, valve means to cut off said pipeconnectionfrorn the source of vacuum, means to connect the source ofvacuum to the top of said second tank, the height of the U bends in saidpipe being such that for a given magnitude of the source of vacuumapplied to the said second tank, the heavy density fluid can be liftedto the height of the inverted U adjacent the first of said tanks andspill over but is insufiicient to effect flow from the first to thesecond tank, said valve means being opened temporarily to apply a vacuumto said barometric leg and evacuate the air therefrom and from the pipeadjacent said first mentioned tank to effect a continuous flow of theheavy density fluid through the system from the first to the secondtank.

4. In a system for transferring heavy density fluid from the top of onetank to the top, of a second tank comprising, a pipe extending in aseries of reverse U hends underground below and between said tanks, atbarometric leg extending upwards from the top of the reverse U bend insaid pipe adjacent the first of said tanks, a source of vacuum, means toconnect the source of vacuum to the top of said second tank, the heightof the U bends in said pipe being such that for a given magnitude of thesource of vacuum applied to the said second tank, the heavy densityfluid can be lifted to the height of the inverted U adjacent the firstof said tanks and spill over but is insufficient to eifect flow from thefirst to the second tank, means to connect the source of vacuumtemporarily to said barometric leg to evacuate the air therefrom andfrom the said pipe adjacent the said first mentioned tank, the vacuumcreated in said second tank thereafter drawing the fluid from the firsttank through the reverse U bend pipe into the second tank.

5. in a system for transferring heavy density fluid from the top of onetank to the top of a second tank comprising, a pipe extending in aseries of reverse U bends underground below and between said tanks, saidpipe terminating in stand pipes extending downwards to adjacent thebottom of said tanks, a barometric leg extending upwards from the top ofthe reverse U bend in said pipe adjacent the first of said tanks, asource of vacuum, means to connect the source of vacuum to the top ofsaid second tank, the height of the U bends in said pipe being such thatfor a given magnitude of the source of vacuum applied to the said secondtank, the heavy density fluid can be lifted to the height of theinverted U adjacent the first of said tanks and spill over but isinsufficient to effect flow from the first to the second tank, means toconnect the source of vacuum temporarily to said barometric'leg toevacuate the air therefrom and from the piping adjacent the said firstmentioned tank, the vacuum created in said second tank thereafterdrawing the fluid from the first tank through the reverse U bend pipinginto the second tank.

6. In a system for transferring heavy density fluid from the top of onetank to the top of a second tank comprising, a pipe extending in aseries of reverse U bends underground below and between said tanks, abarometric leg extending upwards from the top of the reverse U bend pipeadjacent the first of said tanks, a source of vacuum, a balance pipeconnection connecting said barometric leg with the source of vacuum,valve means separating said barometric leg and balance pipe connectionfrom said reverse U bend pipe and said second tank, means to connect thesource of vacuum to the top of said second tank, the height of the Ubends in said pipe being such that for a given magnitude of the sourceof vacuum applied to the said second tank, the heavy density fluid canbe lifted to the height of the inverted U adjacent the first of saidtanks and spill over but is insufficient to effect flow from the firstto the second tank, said valve means when opened temporarily permittingevacuation of air from the said barometric leg and from the firstmentioned tank and from said pipe and thereafter, when closed, shuttingoff the source of vacuum from the barometric leg and balance pipeconnection and eifecting a continuous flow of the high density fluidthrough the reverse U bend pipe from the first to the second tank.

References Cited in the file of this patent UNITED STATES PATENTS GoetzNov. 5, 1889 Thomas Aug. 27, 1935 Auter Oct. 22, 1935 Tokheim Sept. 29,1936 Robertson Dec. 30, 1952

